1. Field of the Invention
The present invention relates to the transmission of electro-magnetic energy. More particularly the invention relates to the transmission of millimeter waveguided energy in gimballed systems. In still further particularity the invention may be described as a millimeter wave dielectric waveguide joint for use in gimballed electronic applications.
2. Description of the Prior Art
Rotating joints are used in a number of electronics applications, such as missile seeker homing systems, conical scan direction finding systems, scanning radars and in antenna range measurement facilities. During recent years the military has become increasingly interested in millimeter wave systems. The current waveguide rotary joints available for use at millimeter wave frequencies are considered to be deficient in at least three aspects, to-wit:
a. Transmission loss is too high for millimeter-wave frequencies and thus results in performance limitations on the military hardware fielded; PA1 b. Performance degrades appreciably with increases in field use, resulting in severe maintenance problems for fielded systems using these devices; PA1 c. The cost of these devices is extremely high.
Presently known rotary joints use at least two metallic waveguides relatively rotatable to achieve the desired result; these waveguides must be physically separated yet give the electrical appearance of continuity. Most joints contain a choke flange, which requires machining quarterwave length grooves thereinto, to insure good electrical contact between the mechanically split sections. For millimeter wavelength applications this requires very intricate machining of the joint.
Further, unless metallic waveguides are charged with inert gas, their interior surfaces are subject to corrosion which can result in degradation of the transmitted signal.